US6702447B2 - Projection display system - Google Patents

Projection display system Download PDF

Info

Publication number
US6702447B2
US6702447B2 US10/065,954 US6595402A US6702447B2 US 6702447 B2 US6702447 B2 US 6702447B2 US 6595402 A US6595402 A US 6595402A US 6702447 B2 US6702447 B2 US 6702447B2
Authority
US
United States
Prior art keywords
projection display
display system
light
light valve
field lens
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US10/065,954
Other languages
English (en)
Other versions
US20030107715A1 (en
Inventor
Sze-Ke Wang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Coretronic Corp
Original Assignee
Coretronic Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Coretronic Corp filed Critical Coretronic Corp
Assigned to CORETRONIC CORPORATION reassignment CORETRONIC CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: WANG, SZE-KE
Publication of US20030107715A1 publication Critical patent/US20030107715A1/en
Application granted granted Critical
Publication of US6702447B2 publication Critical patent/US6702447B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G03B21/28—Reflectors in projection beam

Definitions

  • the present invention relates to a projection display system, and more particularly, to a projection display system capable of diminishing ghost images.
  • projection display devices become popular both in an office and at home.
  • a projection display device projects images on a display, in the meantime, generating some blurs, such as ghost images. ghost images downgrade the performance of projected images and consequently become a concern to design the projection display device.
  • FIG. 1 is a projection display system 10 according to the prior art
  • the projection display system 10 comprises an illumination system 110 and an image system 120 .
  • white light beams emitted by a light source 111 and reflected from a reflector 112 , converge onto a color generator 113 , such as a color wheel.
  • the color generator 113 comprises a series of red, green, and blue filters for transforming the white light beams into colored light beams.
  • the colored light beams sequentially pass through a light-uniform device 114 , such as an integration rod or a lens array, and through an illumination lens set 115 and reach a reflection mirror 116 .
  • the reflection mirror 116 reflects the colored light beams through a field lens 117 and finally onto a light valve 121 , such as a digital micro-mirror device (DMD). Reflected by the light valve 121 , the colored light beams, which are projected onto the light valve 121 , pass through the field lens 117 again. The colored light beams then penetrate through a projection lens 122 and project onto a screen 124 , composing the image system 120 .
  • a light valve 121 such as a digital micro-mirror device (DMD).
  • the light valve 121 which is mounted on a substrate, is formed with a plurality of pixel lenses disposed in a matrix, each pixel lens being capable of pivotably rotating around an axis within a range of 12 degrees.
  • the pixel lenses reflect an incident light beam onto a region inside of the projection lens 122 and the incident light beam can project onto the screen 124 when the light valve 121 is in an ON-state.
  • the pixel lenses reflect an incident light beam onto a region outside of the projection lens 122 and, of course, outside of the screen 124 when the light valve 121 is in an OFF-state.
  • FIG. 2A to FIG. 2C show light paths of ghost images of the projection display system 10 according to the prior art.
  • the white light beams, emitted by the light source 111 will sequentially pass through the color generator 113 , the light-uniform device 114 , the illumination lens set 115 , the reflection mirror 116 , and the field lens 117 , and project onto the light valve 121 .
  • the light valve 121 reflects the colored light beams onto the field lens 117 again and a first surface 1171 of the field lens 117 reflects the colored light beam back onto the light valve 121 , generating second reflection colored light beams. As shown in FIG. 2A to FIG. 2C, the light valve 121 still reflects the second reflection colored light beams through the projection lens 122 and onto the screen 124 , forming so-called ghost images 1241 .
  • a corresponding focal point F located on a position near the light valve 121 and corresponding to the ghost images 1241 forms a virtual ghost-image light source 1211 , which is extended along a direction from the focal point F toward the light valve 121 .
  • the virtual ghost-image light source 1211 projects colors light beams onto the screen 124 to generate the ghost images 1241 .
  • the ghost images 1241 undoubtedly downgrade the performance of the projection display system 10 .
  • FIG. 3A to FIG. 3C are schematic diagrams of a first projection display system capable of diminishing ghost images according to the prior art.
  • a convex surface with a curvature radius R less than 50 mm is formed on a first surface 1172 of the field lens 117 .
  • the convex surface reflects and focuses the reflected colored light beams to a focal point F 1 between the light valve 121 and the convex surface.
  • the reflected colored light beams continue to travel toward the light valve 121 to form a light-spreading area 1212 .
  • the light valve 121 reflects the reflected colored light beams onto the screen 124 through the projection lens 122 , forming spreading images 1242 and diminishing ghost images.
  • the spreading images 1242 are not ghost images, but reduced contrast for the first projection display system.
  • FIG. 4A to FIG. 4C are schematic diagrams of a second projection display system capable of diminishing ghost images according to the prior art.
  • a convexo-concave surface with a curvature radius R less than 0 mm is formed on a first surface 1173 of the field lens 117 .
  • the convexo-concave surface diverges the reflected colored light beams toward the light valve 121 to form a light-spreading area 1213 .
  • the light-spreading area has a virtual focal point F 2 .
  • the light valve 121 reflects the reflected colored light beams onto the screen 124 through the projection lens 122 , forming another spreading images 1243 .
  • the spreading images 1243 are not ghost images either, but also reduced contrast for the second projection display system.
  • the projection display system includes an illumination system and an image system.
  • the projection display system has a light source for emitting at least one light beam, and a field lens having a first surface and a second surface opposite to the first surface, the first surface having at least one reflection area.
  • the image system utilizes the field lens and a light valve mounted adjacent to the second surface of the field lens for reflecting the light beam emitted by the light source. The light beam reflected from the light valve to the interface reflecting area is further reflected to a region outside of the light valve by the reflection area.
  • a projection display system can diminish ghost images by using the field lens with appropriate curvature radius to reflect unwanted light beams to a region outside of the light valve of the projection display system.
  • FIG. 1 is a schematic diagram of a projection display system according to the prior art.
  • FIG. 2 is a schematic diagram showing how the projection display system of FIG. 1 generates image ghosts.
  • FIGS. 3A to 3 C are schematic diagrams of a projection display system that can diminish ghost images according to the prior art.
  • FIG. 4A to FIG. 4C are schematic diagrams of another projection display system that can diminish ghost images according to the prior art.
  • FIG. 5 is a schematic diagram of a projection display system according to the present invention.
  • FIG. 6 is a schematic diagram of way of diminishing ghost images according to the present invention.
  • FIG. 7 is a schematic diagram of another way of diminishing ghost images according to the present invention.
  • FIG. 5 shows a projection display system 20 according to the present invention.
  • the projection display system 20 comprises an illumination system 210 and an image system 220 .
  • white light beams emitted by a light source 211 and reflected from a reflector 212 converge onto a color generator 213 , such as a color wheel.
  • the color generator 213 comprises a series of red, green, and blue filters for transforming the white light beams into colored light beams.
  • the colored light beams sequentially pass through a light-uniform device 214 , such as an integration rod or a lens array, and through an illumination lens set 215 , and reach a reflection mirror 216 .
  • the reflection mirror 216 reflects the colored light beams through a field lens 217 and finally onto a light valve 221 , such as a digital micro-mirror device (DMD). Reflected by the light valve 221 , the colored light beams which were projected onto the light valve 221 pass through the field lens 217 again. The colored light beams then penetrate through a projection lens 222 and project onto a screen 224 , composing the image system 220 .
  • a light valve 221 such as a digital micro-mirror device (DMD).
  • the white light beams that are emitted by the light source 211 will sequentially pass through the color generator 213 , the light-uniform device 214 , the illumination lens set 215 , the reflection mirror 216 , and the field lens 217 , and project onto the light valve 221 .
  • the light valve 221 then reflects the colored light beam directly through the projection lens 222 and onto the screen 224 .
  • the white light beams that are emitted by the light source 211 will sequentially pass through the color generator 213 , the light-uniform device 214 , the illumination lens set 215 , the reflection mirror 216 , and the field lens 217 , and project onto the light valve 221 .
  • the light valve 221 then reflects the colored light beams onto a reflection area 2172 that is formed on a first surface 2171 of the field lens 217 .
  • the reflection area 2172 is disposed in a region adjacent to boundary of the first surface 2171 .
  • the reflection area 2172 reflects colored light beams reflected from the light valve 221 to a region outside of the light valve 221 , diminishing ghost images originated from the prior art second reflection colored light beams.
  • the reflection area 2172 is specifically designed. According to an experiment for the present invention, a curve is applied to form the first surface 2171 by pivoting around an axis. The equation for the curve is
  • R is the curvature radius and ranges between 50 mm and 500 mm
  • K, A, B, C and D are variables according to the projection display system 20 . For example, if R equals 80 mm, K ⁇ 0, A ⁇ 2.3892 ⁇ 10 ⁇ 6 , B ⁇ 7.2980 ⁇ 10 ⁇ 8 , C ⁇ 2.5287 ⁇ 10 ⁇ 10 , and D ⁇ 2.9488 ⁇ 10 ⁇ 13 .
  • FIG. 6 is a schematic diagram of a first embodiment according to the present invention.
  • the reflection area 2172 is a non-spherical surface.
  • the reflection area 2172 having a curvature radius R can reflect the incident light beams to a region outside of the light valve 221 . Therefore, the incident light beams will not enter the projection lens 222 and project onto the screen 224 , diminishing ghost images.
  • the curvature radius R ranges between 50 mm to 500 mm.
  • FIG. 7 is a schematic diagram of a second embodiment according to the present invention.
  • a reflection area 3172 of a first surface 3171 on a field lens 317 is a spherical surface.
  • the curvature radius R of the spherical surface also ranges between 50 mm to 500 mm. For example, if the curvature radius R is 500 mm, the reflection area 3172 will reflect incident light beams to a region outside of the light valve 321 . Therefore, the incident light beams will not enter the projection lens 222 and project onto the screen 224 , diminishing ghost images too.
  • the present invention can provide a projection display system to diminish ghost images with a specifically designed field lens.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Projection Apparatus (AREA)
  • Lenses (AREA)
  • Mechanical Light Control Or Optical Switches (AREA)
  • Transforming Electric Information Into Light Information (AREA)
US10/065,954 2001-12-06 2002-12-04 Projection display system Expired - Lifetime US6702447B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
TW90130586A 2001-12-06
TW090130586 2001-12-06
TW090130586A TW494270B (en) 2001-12-06 2001-12-06 Projection system to improve the ghost image of picture

Publications (2)

Publication Number Publication Date
US20030107715A1 US20030107715A1 (en) 2003-06-12
US6702447B2 true US6702447B2 (en) 2004-03-09

Family

ID=21679905

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/065,954 Expired - Lifetime US6702447B2 (en) 2001-12-06 2002-12-04 Projection display system

Country Status (4)

Country Link
US (1) US6702447B2 (de)
JP (1) JP3848246B2 (de)
DE (1) DE10256711A1 (de)
TW (1) TW494270B (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040145793A1 (en) * 2003-01-28 2004-07-29 Barbour Michael J. Multiple-bit storage element for binary optical display element
US20050275812A1 (en) * 2004-06-15 2005-12-15 Samsung Electronics Co.,Ltd. Projection system
US20080079911A1 (en) * 2006-10-02 2008-04-03 Coretronic Corporation Projection apparatus

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10325867B4 (de) * 2003-06-06 2013-08-01 Eberhard Piehler Projektionsvorrichtung
US7101063B2 (en) 2004-02-05 2006-09-05 Hewlett-Packard Development Company, L.P. Systems and methods for integrating light
US8649101B2 (en) 2010-08-19 2014-02-11 Young Optics Inc. Projection apparatus
TWI418920B (zh) 2011-03-31 2013-12-11 Young Optics Inc 投影裝置
US20140368797A1 (en) * 2013-06-12 2014-12-18 Texas Instruments Incorporated Methods and apparatus for reducing ghost images in reflective imager-based projectors
KR20150114763A (ko) * 2014-04-02 2015-10-13 삼성전자주식회사 프로젝터

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4981352A (en) * 1988-12-14 1991-01-01 Asahi Kogaku Kogyo Kabushiki Kaisha Projection display device
US5268775A (en) * 1991-02-19 1993-12-07 Hughes-Jvc Technology Corporation Contrast enhancement and ghost elimination, for reflective light valve system
US6500378B1 (en) * 2000-07-13 2002-12-31 Eom Technologies, L.L.C. Method and apparatus for creating three-dimensional objects by cross-sectional lithography
US6522453B2 (en) * 2000-09-28 2003-02-18 Fuji Photo Optical Co., Ltd. Projection device and a projection lens
US6557999B1 (en) * 2000-11-16 2003-05-06 Koninklijke Philips Electronics N.V. System and method for contrast enhancement in projection imaging system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4981352A (en) * 1988-12-14 1991-01-01 Asahi Kogaku Kogyo Kabushiki Kaisha Projection display device
US5268775A (en) * 1991-02-19 1993-12-07 Hughes-Jvc Technology Corporation Contrast enhancement and ghost elimination, for reflective light valve system
US6500378B1 (en) * 2000-07-13 2002-12-31 Eom Technologies, L.L.C. Method and apparatus for creating three-dimensional objects by cross-sectional lithography
US6522453B2 (en) * 2000-09-28 2003-02-18 Fuji Photo Optical Co., Ltd. Projection device and a projection lens
US6557999B1 (en) * 2000-11-16 2003-05-06 Koninklijke Philips Electronics N.V. System and method for contrast enhancement in projection imaging system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
US 2003/0058414 A1. *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040145793A1 (en) * 2003-01-28 2004-07-29 Barbour Michael J. Multiple-bit storage element for binary optical display element
US20050062766A1 (en) * 2003-01-28 2005-03-24 Barbour Michael J. Multiple-bit storage element for binary optical display element
US6888657B2 (en) * 2003-01-28 2005-05-03 Hewlett-Packard Development Company, L.P. Multiple-bit storage element for binary optical display element
US7161609B2 (en) 2003-01-28 2007-01-09 Hewlett-Packard Development Company, L.P. Multiple-bit storage element for binary optical display element
US20050275812A1 (en) * 2004-06-15 2005-12-15 Samsung Electronics Co.,Ltd. Projection system
US7401930B2 (en) * 2004-06-15 2008-07-22 Samsung Electronics Co., Ltd. Projection system
US20080079911A1 (en) * 2006-10-02 2008-04-03 Coretronic Corporation Projection apparatus
US7837337B2 (en) * 2006-10-02 2010-11-23 Coretronic Corporation Projection apparatus

Also Published As

Publication number Publication date
JP2003185965A (ja) 2003-07-03
US20030107715A1 (en) 2003-06-12
TW494270B (en) 2002-07-11
DE10256711A1 (de) 2003-08-21
JP3848246B2 (ja) 2006-11-22

Similar Documents

Publication Publication Date Title
US8059340B2 (en) Method and system for reducing speckle by vibrating a line generating element
US7959305B2 (en) Light recycling in a micromirror-based projection display system
JP3065058B1 (ja) プロジェクタ用光学系
US7784950B2 (en) Image projecting apparatus having variable stop
KR100382953B1 (ko) 화상표시장치
US6637894B2 (en) High contrast projection
CN100573308C (zh) Dlp光学系统
JP3191792B2 (ja) プロジェクタ用光学系
JP2003295110A (ja) 画像表示装置
CN102799055A (zh) 不具有中继透镜的图像投影设备
US6702447B2 (en) Projection display system
US6799852B2 (en) Image display projector
US20110199581A1 (en) Optical projection system and method for reducing unessential beams formed therein
JP3720678B2 (ja) 照明光学装置および投写型表示装置
US6898008B1 (en) Front projection screen
US7290886B2 (en) Illuminating system and method for improving asymmetric projection
US6840631B2 (en) Illuminating apparatus, and projector using the illuminating apparatus
KR20020077344A (ko) 비디오프로젝터용 조명 광학 시스템
JP2006308992A (ja) 投写型表示装置及び投写光学系
CN105607405B (zh) 一种投影屏幕
US20030107714A1 (en) Method and system for improving asymmetrical projection
JP2002169222A (ja) ストレイライト除去機能を有する光学システム
JP2004138881A (ja) 画像投影表示装置
JP2002207190A (ja) リアプロジェクションテレビ及びその投射方法
JP2002107822A (ja) プロジェクタ装置および投映レンズ

Legal Events

Date Code Title Description
AS Assignment

Owner name: CORETRONIC CORPORATION, TAIWAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:WANG, SZE-KE;REEL/FRAME:013277/0540

Effective date: 20021127

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12

FEPP Fee payment procedure

Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY